butler lie
n. A lie used to politely avoid or end an email, instant messaging, or telephone conversation.
The Butler lie is a recent nomenclature coined by researchers at Cornell University. It's a smaller lie which is conveyed electronically and used to end a conversation. The next time your friend texts that he has to end the conversation with you because the waiter arrived, just maybe your friend isn't even at a restaurant.
—Donna Pinter, “Liar, liar, pants on fire,” The Republican Herald, September 04, 2011
Yet technology is already laying siege to the butler lie. Services like BlackBerry Messenger enable mutual users to track when their texts are read, effectively torpedoing the ''sorry, phone died last night'' excuse. ''Friend tracking'' applications like Google Latitude allow people to geographically pinpoint their friends' mobile phones. So much for ''stuck in traffic'' when you really overslept.
—Austin Considine, “New Technology, But the Same Old Lies,” The New York Times, July 10, 2011
2009 (earliest)
We refer to these types of lies, in which deception is used to manage the entry and exit of social interactions, as butler lies…. Butler lies include the strategies of using deception to "avoid interaction" and to "take leave of interaction" described by Camden [9]. We use the term "butler lies" to allude to the social buffering function that butlers provided for their employers.
—Jeff Hancock, et al., “Butler Lies: Awareness, Deception, and Design” (PDF), Cornell University, April 07, 2009